jim harbaugh played for a string of nfl teams. it is the first time in history this has happened. brother on brother matchup will be a heavy story line in the leadup to the game. we'll have a lot more coming up over the course of this hour, more inauguration coverage ahead. let us no he what you think. follow me on twitte twitter @andersoncooper. i'll be tweeting. the next four years, how has president obama changed the country and how has washington changed the presidency? is this the same man he was four years ago? jodi cantor wrote a story about it, and joins us next. >>> in the face of our common dangers, in this winter of our hardship, let us remember these timeless words. with hope and virtue, let us brave once more the icy currents and endure what storms may come. let it be said by our children's children that when we were tested, we refused to let this journey in. >> president obama's first inaugural address four years ago, we're back in the first few hours of president obama's second term. four years ago, of course, at a time of crisis, he offered hope and promised change